1. Field of the Invention
The present invention relates to a mixing device for mixing the contents of a container.
2. Description of the Related Art
Containers for blending or circulating substances are used in many industrial fields. In the production of culture media for microorganisms or in controlled biotechnological processes such as cell cultivation the blending or the circulation of the container contents is particularly important. Because of the different initial concentrations of the substances as well as the metabolic activity of the microorganisms during the cultivation, local concentration changes of the most varied chemical components in the media batch or of nutrients, oxygen and the metabolites produced occur during the cultivation. In order to ensure the same or at least controlled concentration conditions in the entire container, it is necessary to blend or circulate the liquid or suspension in the container during the entire process.
The use of flexible disposable bioreactors made of foils is continually gaining in importance in particular with regard to the constantly increasing requirements for the sterility of the processes in bioprocess engineering in comparison to rigid containers made of glass or stainless steel. In addition to good sterilizability, foil bags offer further advantages such as cost-effective production, simple and space-saving storage, the best possible safety with regard to contamination and the omission of costly cleaning after use.
The blending of the contents of the flexible disposable bioreactor takes place both mechanically with the aid of agitator elements and also by means of the motion of the container with the liquid itself contained therein. In particular, when disposable flexible containers are used, it is considered advantageous to employ mixers without agitators, since no holes through the container wall are necessary for driving agitator elements. Depending upon the type of movement, such mixers are known as rockers, platform shakers, tumble mixers, circular shakers, vibratory shakers, horizontal shakers, orbital shakers, etc.
Depending upon the field of use, flexible containers can have different sizes, wherein larger containers can have volumes of several liters. Most pre-filled containers are usually arranged on plate-shaped or dish-shaped movable supports, and they are fixed on the supports, for example, by means of clamps or hooks or other releasable fastening means. The supports are driven and generate the mixing movement of the contents of the container. In this case the support carries out, for example, a rocking movement about a horizontal position.
In order to remove the contents from the bags again, the supports with the bags fixed thereon can be moved into an almost vertical position. Filling of the containers in the vertical position is also optionally possible.
WO 2012/115581 A1 discloses a bioreactor with a mixing device, in which a container support carries out a rocking movement about a horizontal rocking axis for mixing the contents of a container. A set-up axis, around which the container support can be pivoted in order to set up the container support, is arranged on a front end of the container support, wherein the set-up axis extends parallel to the rocking axis. In order to simplify the removal of products from the container, the container support in the set-up state can be inclined toward a corner of the container about a second tilting axis which extends perpendicular to the set-up axis. However, due to the provision of a set-up axis, on the one hand, and a tilting axis perpendicular thereto, on the other hand, the design of the mixing device is complex and disadvantageous.
The object of the present invention is to provide an improved mixing device which can move a container in a simple manner into an advantageous filling or removal position.
This object is achieved by the subject matter of the independent claim. Advantageous embodiments are disclosed by the dependent claims.